1. Field of the Invention
This invention relates to a method of forming a laminate and more particularly, to a method of forming a laminate by means of an explosive.
2. Description of the Prior Art
There are numerous industrial applications which require forming a pattern of metal-plated areas on an insulating substrate. One such application is in forming printed circuit boards. Often times when a printed circuit board is fabricated, defects occur in the formed metallic patterns which necessitate the repair of such defective patterns. Such repairs are often done by electroless and/or electroplating techniques or by solder bonding a shaped metal overlay to the defective pattern. However, these existing techniques are not practical and are costly and time consuming.
Selected portions of a metallic pattern, such as on a printed circuit board must often be coated with a different metal such as gold which is used for contact purposes. Again, such a coating has been accomplished by means of electroless and/or electroplating techniques which are costly and time consuming.
A method of forming a laminate which is rapid and does not require electroless and/or electroplating techniques is therefore desired. Explosive bonding techniques have been used for bonding one surface to another. In this regard, reference is made to U.S. Pat. No. 3,736,654 which discloses a method of explosively bonding a first workpiece to a second workpiece, and to U.S. Pat. No. 3,474,520 which reveals a process for explosively laminating a metal film to a base.
However, the methods of explosively bonding a metal film to a pattern have never been carried out without first shaping the metal film to conform to the pattern to which it is destined to be bonded. An explosive bonding method which eliminates this costly shaping step and the alignment associated therewith is therefore needed.